The invention relates to room temperature curable organopolysiloxane compositions and more particularily to elastomers prepared therefrom.
Compositions which can be stored under anhydrous conditions, but when exposed to atmospheric moisture cure to an elastomer at room temperature are well known in the art. U.S. Pat. No. 3,677,996 to Kaiser et al discloses, for example a composition containing a diorganopolysiloxane having terminal condensable groups, a silicon compound having at least one nitrogen atom and at least three hydrolyzable groups per molecule and a reinforcing filler which cures to an elastomeric solid when exposed to atmospheric moisture at room temperature.
When the compositions known heretofore are compared with the compositions of this invention, it was found that the compositions of this invention cure faster than the conventional compositions. Moreover, the compositions of this invention have better flow properties and can therefore be inserted into narrow apertures at a faster rate. Also the compositions of this invention exhibit improved stability. Furthermore, elastomers prepared from these compositions have a lower modulus value at 100 percent elongation even though they contain the same amount of filler as used in the room temperature curable compositions known heretofore.
Therefore, it is an object of this invention to provide a room temperature curable organopolysiloxane composition having improved stability. Another object of this invention is to provide a room temperature curable composition having improved flow properties. A further object of this invention is to provide elastomers having improved modulus at 100 percent elongation.